2-cycle oil ratios?

[s219]

From what I have read, it's more about the oil's capability. The new oils are capable of 50:1 while still providing proper lubrication. Doesn't matter what is written in the equipment user manual. Older equipment will show 32:1 or 16:1 just because that's what the oil of that era was capable of, but they should run fine on the new 50:1 oils. Been doing that for 4-5 years now, and I am sure I would have noticed a problem by now.

 

[2458n]

Why not use the stuff that says it is designed for all mix ratios? I run it with 94 octane gas. Fill about 5 gallons from the pump in truck first and then fill my 2 gallons into the 2 stroke can with the oil. It comes in a flat plastic package. Run it in every yard thing that I have.

 

[ultrarunner]

^^^ Makes sense...

I guess it wouldn't take long brush cutting with the wrong oil to know a mistake was made...

I still have unopened cans and bottles or Echo, Stihl, Evinrude, Tanaka and Sears 2 cycle oil...

It's brush cutting season because in 4 weeks the fire inspections start... the 33 year old Kubota SRM300 was just humming away today... it was down because the fuel tank had cracked and so far the fuel tank repair epoxy is holding...

I like the Stihl mix as well as Echo and Tanaka... Tanaka has a great mix bottle to measure built in so I keep that one in the truck.

 

[MossRoad]

Just went through all of my 2-cycle equipment...

I have the following ratios:

16 to 1

20 to 1

32 to 1

40 to 1

50 to 1

Hoping not to have to keep 5 cans of different mix on hand... the store bought pre mix that is alcohol free is 50 to 1

Never had a piston seize so I must be doing something right and yet, I hear people say the premium 50 to 1 can be used in 32 and 40 to 1 ratios...

Do you keep different mixes for all your 2 cycles?

The 16 to 1 ratio is for the old outboard evinrude circa 1958, a 1939 97cc motorcycle and a very old craftsman chain saw.

The Echo Brush Cutter circa 1982 is 20 to 1 and all the other stuff is much newer.

Without thinking today I ran about 1/2 a tank of 50 to 1 Stihl mix in the 20 to 1 Echo Brush Cutter... seemed to work fine.

As others have mentioned... DON'T use marine grade 2 cycle oil in an air cooled engine. It won't stand up to the heat that an air cooled engine generates.

I have several pieces of lawn equipment that vary from 32:1, 40:1 and 50:1. I just use one gas can with 40:1 for all of them. Never had a problem in decades.

I did have a Yamaha RD400 two stroke twin that seized up on me when its oil injection pump failed. But that was a mechanical issue.
I've had chainsaws seize up after loaning them to friends due to wrong/no mixture.

For your vintage stuff, I'd say why chance it? If you've been feeding them the correct mixture for so many years and they've lasted this long, then why change? Its fairly easy to just mix up a quart of proper mixture. Or a gallon or two or three....

And lets say you mix up a gallon of 20:1 and only use a quart of it. Just add 3 qts of gas and you have a gallon and a half of 40:1.

As a general rule of thumb, going to a higher mixture, like 40:1 in something that requires 50:1 won't hurt anything. Sure, its 20% more oil than it needs, but I doubt you'll see any difference. Again, its better to have to clean something every few years than repair something every few years.

 

[Sysop]

Would any of you run your tractors with not enough oil?

 

[Sodo]

In the old days nobody really knew how much oil was required. But the biggest thing was nobody cared about water quality, air quality, so mfrs just recommended "more oil". Why not, right?

Then the gub'mint looks at the yearly sales of 2-stroke oil, "KNOWING" that every last drop of the hundreds of thousands of gallons is by design, intended to be spread all over the countryside, so gub'mint has to DO something, so starts to talk about banning the 2-stroke engine.

The manufacturers respond.

Mfrs don't want 2-stroke engines banned so they study the situation and discover that 50:1, with modern oils, is plenty oil. Sufficient yet only pollutes 1/3 to half as much as the old days (and costs less too).

==============

One problem you can run into with 2-strokes is some of them are very sensitive to the fuel/air ratio. If you have an engine that is jetted to run at 20:1 and you put 50:1 mix in it, you have richened your fuel/air mixture by a lot. Plus the fuel is a little less viscous too and goes thru the jets faster. So anyway you may have to go a size smaller for a carburetor jet, or reset your mixture screws.

Luckily using less oil results in a richer mixture, which burns cooler. As opposed to the other way around, for example running 32:1 in a 50:1 engine is a leaner condition, can cause the engine to run hotter, and with 2-strokes that can be dangerous to the piston. For the hotter (leaner) condition you may be glad you put more oil in it, but you didn't need to.

==============

I use 50:1 in all my small engines. In my motorcycles I run 80:1.

 

[ultrarunner]

I noticed almost no smoke when I had the 50 to 1 in the tank...

It's a different story when 20 to 1 is used.

Interesting how changing the ratios has a domino affect.

I wonder what affect 10% alcohol has since I'm certain it was never thought of 30+ years ago when my Echo was made?

 

[Sodo]

I wonder what affect 10% alcohol has since I'm certain it was never thought of 30+ years ago when my Echo was made?

Check your calendar. 30 years ago was 1985.

Many major US cities had attrocious air quality, and by then the newer cars had smog controls but all the old cars were belching out pollution at unbelievable rates. Like China today.

A modern car puts out a small fraction of the pollution of a '70s car. I have a friend who was bragging about his '70 VW bus (being more ecological than a chevy pickup) and I pulled out his smog check papers, the pollution allowables for that '70 bus allowed 300 times the pollution for a modern 350 chevy V8. So one '70 VW bus = 300 chev V8s (with respect to SOME of the pollutants).

Point being, 10% alcohol was "thought of" 30 years ago. It was one of the fuels of the future. One of the ways we could retain our car culture - yet still breathe. And not choke like China.

 

[ultrarunner]

There is a family mower shop that I've been ordering parts the last 40 or so years... the owner can't keep quarts of non-alcohol fuel in stock fast enough and the same is for the local Home Depot and even on sale the price can be $15+ a gallon.

It's also been great for business... has one guy that only works on fuel related problems and always has a backlog...

Carb and all fuel issues were a small part of the business back in the 70's and California had already switched to unleaded fuels then...

You just know there has to be compatibility issues when local airports won't fuel with alcohol...

My Brush Cutter gets about 3 full days of use each Spring... sun up to sun down and then it is run dry and put up in the shop for next season.

On a side note... my Model A's and Model T's have no problems with various types of fuel... the fuel system is all metal... no rubber to be found anywhere... guess it is one reason for their longevity...

 

[buickanddeere]

I was told that professional lawncare services, likely having a plethora of mix requirements, just keep a jug of 32:1 for all of it. Don't know if this is/was true.

The 32 to 1 one mix is to save an engine if someone fills the fuel tank with 100% gasoline .